Abstract

We report a comprehensive study of orbital characters and tridimensional nature of the electronic bands of 111-family in Fe-pnictides superconductors, (x = 0 and 0.05), with angle-resolved photoemission spectroscopy. We determined the orbital characters and the dependence of the low-energy electronic structures by tuning the polarization and the energy of the incident photons. We observed two nearly two-dimensional hole-like Fermi surfaces (FS) near the Brillouin zone (BZ) center and two electron-like FS near BZ corner. The bands near the Fermi level () are mainly derived from the Fe , and orbitals.

Received 08 April 2012Accepted 30 October 2012Published online 13 November 2012

Acknowledgments:

This work was supported by the grants from the Chinese Academy of Sciences, the Ministry of Science and Technology of China, the National Science Foundation of China, the Fundamental research Funds for the central university and the Research Funds of RUC. The National Synchrotron Light Source is supported by the US Department of Energy. The Synchrotron Radiation Center, Stoughton (WI) is supported by the National Science Foundation under Award No. DMR-0537588.